Farm 'graveyards', those piles of abandoned vehicles and rusty machinery that dot rural landscapes, are like cherished living photo albums and family heirlooms.

That's the conclusion of Di Smith, a PhD candidate at Flinders University of South Australia, after studying the archaeology of farm graveyards.

Her study, believed to be the first of its type in Australia and possibly the world, found these graveyards, are part of our cultural heritage and of great archaeological value.

"I was looking for the answer to my questions of why do farmers keep all these abandoned vehicles and machinery on their property, why do they keep them for so long, and what do they do with them?" Smith says.

Of the nearly 150 farmers who responded, 60% said they had farm graveyards, many of them inherited.

Of those that didn't have sites, many said they used to have one and regretted getting rid of it to the scrap dealer.

"To farmers [these sites] were very special and had a very useful purpose in recycling. It became very clear to me that they were not just rubbish dumps where [farmers] disposed of stuff and never looked at it again," Smith says.

She followed up her questionnaire by conducting detailed artefact surveys and inventories, mapping the sites and recording the histories of 16 farm graveyard sites across South Australia and Victoria. She then looked at sites in Alberta, Canada.

Sites in Australia and Canada share many similarities, Smith says.

"[But] Canadian farmers were very neat in their approach, often lining [their equipment] up in neat rows along fences, so that they are very accessible."

Both countries' farmers are inventive when it comes to recycling, for instance, using old machinery for spare parts.

Smith says her research gives important insight into the deeper meaning these sites hold for farmers and their families.

"They have an important meaning as an agricultural heritage. It tells farmers who they are, where they've been and where they might be going to as far as a place that encapsulates their cultural heritage," she says.

"To them, [the graveyards are as valuable as] a museum collection or a photo album. Because they can walk through it, and visit all these old friends along the way."